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Conference rusure::math

Title:Mathematics at DEC
Moderator:RUSURE::EDP
Created:Mon Feb 03 1986
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2083
Total number of notes:14613

1335.0. "IVP and Maple" by CSC32::S_JOHNSON (Lifetime Member of Aye Phelta Thi) Sun Nov 11 1990 18:29

Hi,

I know this is not the maple conference, but here goes.

How would I use maple to solve the following initial value problem?

   y'(t) = y(1-tan(t))   1 <= t <= 2  y(0) =   n = 

Thanks for any and all replies.

scott
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1335.1GUESS::DERAMODan D&#039;EramoMon Nov 12 1990 09:2420
	dy
	-- = (1 - tan t)dt
	y

	or

	ln y = t + ln( cos t ) + C

	At t=0, ln y(0) = 0 + ln( cos 0 ) + C = ln 1 + C = C,
	so

	ln y = t + ln ( cos t ) + ln y(0)

	or
		     t
	y(t) = y(0) e  cos t

	I don't know how to do it in Maple. :-)

	Dan
1335.2Oops.CSC32::S_JOHNSONLifetime Member of Aye Phelta ThiMon Nov 12 1990 11:538
    The base note read:

>      y'(t) = y(1-tan(t))   1 <= t <= 2  y(0) =   n = 
    
    It should be:
                                                    
      y'(t) = y(1-tan(t))   1 <= t <= 2  y(1) = 0
    
1335.3GUESS::DERAMODan D&#039;EramoMon Nov 12 1990 14:0621
	Did you ask in the Maple conference (MODEL::MAPLE)?

	Changing the initial condition to y(1) = 0 yields

		ln y = t + ln( cos t ) + C

	and so as before

		       t			     C
		y = k e  cos t			k = e


	Now plugging in y(1) = 0 implies k = 0, so the solution
	is y(t) = 0 for 1 <= t <= 2.  What is happening is that

>>		y'(t) = y(1-tan(t))   1 <= t <= 2  y(1) = 0

	says that when t=1 you have y' = 0, so y is starting at
	zero and staying there.

	Dan